TAMPA, Fla., March 10 /PRNewswire-FirstCall/ -- New data demonstrate that GlaxoSmithKline's (NYSE: GSK) cervical cancer candidate vaccine, CERVARIX(R) provides significant protection for women against the four most common cancer- causing human papillomavirus types for nearly six and a half years, the longest duration of protection reported to date. Over this time, the cervical cancer candidate vaccine showed 100 percent efficacy in preventing precancerous lesions due to cancer-causing virus types 16 and 18 and also provided substantial protection against infection caused by virus types 31 and 45.
These data show that virtually 100 percent of women in the study, 15-25 years of age, maintained high levels of antibodies against both virus types 16 and 18 at every time point for nearly six and half years. This signifies the longest duration of consistently high antibody levels demonstrated by a cervical cancer vaccine. Antibody levels remained several times higher than natural infection levels over the extended period of time.
"With this trial, we continue to see high levels of antibodies that lasted over time in virtually all women studied, which is critical for the prevention of cervical cancer," said Diane Harper, MD, Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, NH. "These data are remarkable as they show the potential for this cervical cancer vaccine to protect women over the long term."
The study also confirmed substantial cross-protection for nearly six and a half years against incident infection caused by virus types 45 and 31. Specifically, the vaccine showed 78 percent efficacy in preventing incident infection caused by virus type 45, and 60 percent efficacy in preventing incident infection caused by virus type 31.
Virus types 18 and 45 are responsible for a significant percentage of a particularly aggressive and deadly form of cervical cancer known as adenocarcinoma. This type of cervical cancer tends to occur in younger women and is not well detected by routine screening methods.
"We specifically designed our cervical cancer vaccine with the goal of providing long-lasting protection from cervical cancer," said James Tursi, MD, Director of Medical Affairs, North America, GlaxoSmithKline. "These study results are important because women remain at risk for infection with cancer- causing virus types throughout their lives, and long-term protection will be an essential component of a successful vaccination strategy."
The results also include safety data from nearly six and a half years, showing that the candidate vaccine had no meaningful differences between the study groups and had a favorable overall safety profile.
These data were presented today at the Society of Gynecologic Oncologists (SGO) annual meeting in Tampa, FL.
Notes to editors
About the study
This was an extended follow-up (EFU) analysis of women who participated in the initial efficacy study of GSK's cervical cancer candidate vaccine. The initial study was a double-blind, controlled trial of 1,113 young women between 15-25 years of age, randomized to receive three doses of the GSK candidate vaccine for cervical cancer formulated with the AS04 adjuvant system, or three doses of placebo on a 0, 1 and 6 month schedule.
This extended follow-up study looked at study endpoints for 776 women from the same cohort of women for a period of up to 76 months. The trial was conducted in 28 centers in Brazil, Canada and the U.S. and evaluated the efficacy, safety and immunogenicity of GSK's cervical cancer candidate vaccine for the prevention of infection with cancer causing virus types 16 and/or 18, and other cancer-causing virus types, as well as associated Pap smear abnormalities and cervical precancerous lesions. In the extended follow up study, women were evaluated for the presence of human papillomavirus DNA by PCR using cervical samples and annual cervical cytology evaluations were performed. Women were referred for colposcopy following protocol guidelines. Women were also assessed for long-term immunogenicity and safety.
About cervical cancer and its progression
Approximately 100 types of human papillomavirus have been identified to date and, of these, approximately 15 virus types are known to cause cervical cancer. Virus types 16, 18, 45 and 31 are responsible for approximately 80 percent of cervical cancers globally. Infection with cancer-causing virus types can lead to the formation of abnormal cells in the cervix, which, over time, may become precancerous or cancerous. It is a necessary precursor of cervical cancer. Throughout their lifetime, women may be exposed to cancer- causing virus types and are potentially at risk of developing cervical cancer.
Worldwide, more than 500,000 women will be newly diagnosed with cervical cancer and over 280,000 women will die from it each year. In the United States, after breast cancer, cervical cancer is the second leading cause of cancer death in women ages 20 to 39.
About the GSK Cervical Cancer Vaccine
To date, CERVARIX(R) has been approved in 55 countries around the world including the 27 member countries of the European Union, Mexico, Australia, Singapore and the Philippines. Licensing applications have been submitted in 28 additional countries including Japan. GSK also submitted CERVARIX(R) to the World Health Organization (WHO) for prequalification in September 2007.
GSK submitted a Biologics License Application (BLA) to the U.S. Food and Drug Administration (FDA) for its cervical cancer candidate vaccine in March 2007.
GlaxoSmithKline--one of the world's leading research-based pharmaceutical and healthcare companies--is committed to improving the quality of human life by enabling people to do more, feel better and live longer. For company information, please visit www.gsk.com/media.
GSK Biologicals (GSK Bio), one of the world's leading vaccine manufacturers, is headquartered in Rixensart, Belgium, where the majority of GlaxoSmithKline's activities in the field of vaccine research, development and production are conducted. GSK Bio employs more than 1,500 scientists, who are devoted to discovering new vaccines and developing more cost-effective and convenient combination products to prevent infections that cause serious medical problems worldwide. In 2006, GSK Bio distributed more than 1.1 billion doses of vaccines to 169 countries in both the developed and the developing world -- an average of 3 million doses a day. Of those vaccine doses, approximately 136 million were doses of combination pediatric vaccines which protect the world's children with up to six diseases in one vaccine.